New Features of the Edison XC30

While the Edison and Hopper systems have similar programming environments and software, there are some key architectural differences between the two systems. This page describes those differences.

Compute nodes

Edison and Hopper both have a total of 24 cores on each compute node. Edison, like Hopper, has two sockets on each compute node, but instead of four "NUMA" memory domains, Edison has only two. Edison uses Intel processors, unlike Hopper which has processors from AMD. Edison's processors have Intel Hyper-Threading (HT) enabled, which means you can run with 48 logical cores per node. At run time you can decide to run with 24 cores per node (the default setting) or 48 logical cores per node.

External Login Nodes

Like Hopper, Edison has 12 login nodes that are "external" to the main compute portion of the system. Since the login nodes are external, you can login, access file systesms and submit jobs when the main compute protion of the sytem is down for maintenance. The login nodes on Edison have 512 GB of memory, compared to 128 GB on Hopper.

Scratch File Systems

Edison has 7.5 PB of scratch spread over three disk partitions. The aggregate I/O bandwidth is 165 GB/sec, while Hopper has 2 PB disk with 70 GB/s I/O bandwidth. All users have a scratch area defined by the environment variable $SCRATCH on one of two smaller scratch partitions. A third larger file system is dedicated to users who have a demonstrated need for large I/O bandwidth. Users can request access to /scratch3 via a web form. Edison uses Cray Sonexion lustre storage system. The default scratch quota is 10TB.